_This_ is the real thing--not my garbled inaccuracies.

'The food which we eat serves three purposes: it builds the body substance, bone, muscle, etc., it produces heat in the body, and it generates vital energy.

Nitrogen in different chemical combinations contributes largely to the manufacture of body substances; the fats produce heat; and the starches and sugars go to make the vital energy.

The nitrogenous food elements we call proteins; the fats and oils, fats; and the starches and sugars (because of the predominance of carbon), we call carbohydrates.
Now in selecting the diet for the day you should take care to choose those foods which give the proteins, fats, and carbohydrates in just the right proportion.'" "Oh, Billy!" groaned Bertram.
"But it's so, Bertram," maintained Billy, anxiously.

"And it's every bit here.